WO2007114286A1

WO2007114286A1 - Electronic mail delivery system and electronic mail delivery program

Info

Publication number: WO2007114286A1
Application number: PCT/JP2007/056944
Authority: WO
Inventors: Tomonori Kadokawa; Takayuki Hatori; Mitsuhide Hukushige
Original assignee: Ntt Communications Corporation; Nippon Telegraph And Telephone East Corporation
Priority date: 2006-03-29
Filing date: 2007-03-29
Publication date: 2007-10-11
Also published as: EP2015529A1; JP2007267248A; JP4157890B2; CN101411145A; EP2015529A4; US20100169425A1

Abstract

A mail address acquiring section (423) acquires destination mail addresses one by one from received envelop information. A mail header processing section (424) deletes unnecessary destination mail addresses from a mail header. An envelop generating section (425) generates envelop information for delivering mail data. Since the unnecessary destination mail addresses are deleted from the mail header and the mail data can be separately transmitted to each destination mail address included in the envelop information, the sender of the electronic mail can send a broadcast mail without leaking mail addresses of others.

Description

Specification

E-mail delivery system and e-mail delivery program

Technical field

The present invention relates to a technique for receiving and relaying electronic mail.

Background art

[0002] In recent years, with the enforcement of the Personal Information Protection Law, the handling of personal information has increased! Email addresses that identify individuals are also recognized as personal information, and the handling of personal information is the most important concern for companies. Some companies set internal rules to prevent other people's email addresses from being displayed in the To field and Cc (Carbon Copy) field of the email header of broadcast emails (e-mails with multiple recipients registered).

[0003] When sending a broadcast mail, do not display the mail address of others in the mail header! In the conventional method, the email sender himself / herself can duplicate the email for each email address and send it individually, or use the Bcc (Blind Carbon Copy) field in the email header. There is. In addition, as disclosed in Japanese Patent Application Laid-Open No. 2004-207785, a mail address listed in the To field of an electronic mail is copied and individually transmitted. “HDE Customers Care” sold by Horizon Digital Enterprise Co., Ltd. is known as a system for sending broadcast mail such as V and direct mail individually using a dedicated server. In order to prevent leakage of confidential information such as personal information, a system that inspects the contents of e-mails when relaying e-mails is the “HDE Mail Filter” sold by Horizon “Digital” Enterprise Co., Ltd. "GUADIANWAL1" sold by Canon System Solutions Co., Ltd. is known.

[0004] However, in the method using the Bcc field, the email address is incorrectly written in the To field or Cc field due to the literacy status of the sender or human error, etc. May be displayed and leak. In addition, the method by which the sender manually duplicates the email and sends it individually is laborious and can be sent. If you make a mistake, you can easily make mistakes.

[0005] The technology described in Japanese Patent Application Laid-Open No. 2004-207785 acquires the mail addresses listed in the mail header and copies and sends the e-mail, so it is deleted from the mail header in the middle. The email address listed in the Bcc field cannot be processed.

[0006] “HDE Customers Care” requires dedicated transmission software that is suitable for sending a large amount of broadcast e-mails such as issuing direct e-mails and e-mail magazines, and is usually used by senders It cannot be sent from mail sending software.

[0007] In [HDE Mail Filter] and [GUADIANWAL1], in order to prevent leakage of confidential information, it is possible to perform processing such as deleting email without relaying email, but the contents of email It is not possible to delete confidential information from a message and relay it.

Disclosure of the invention

[0008] The present invention has been made in view of the above, and an object of the present invention is to easily send a broadcast mail so that the mail address of another person does not leak.

[0009] An electronic mail delivery system according to the present invention includes a first reception unit that receives an envelope including a destination mail address and stores the envelope in a first storage unit, and a mail header corresponding to the envelope A second receiving unit that receives mail data and stores the mail data in a second storage unit; an acquisition unit that acquires each of the destination mail addresses included in the envelope from the first storage unit; and For each of the acquired destination email addresses, the destination memory address other than the destination email address is deleted from the email header of the email data read out by the second storage unit, and the email data is stored in the first email address. 3 so that the mail data is individually delivered to each of the processing unit stored in the storage unit 3 and the transmission destination mail address acquired by the acquisition unit. An envelope including a recipient mail address is generated and stored in a fourth storage unit; the envelope is read from the fourth storage unit; and the envelope included in the envelope from the third storage unit And a delivery unit that reads the mail data corresponding to the destination mail address and delivers the mail data based on the envelope. [0010] In the present invention, an acquisition unit that acquires the destination email addresses one by one from the received envelope, a processing unit that deletes destination email addresses other than the acquired email address from the email header, and an acquisition By providing a generation unit that generates an envelope for delivery to the mail address, an e-mail can be individually transmitted to each of the destination mail addresses included in the envelope. As a result, the e-mail header of the e-mail to be sent should contain a destination e-mail address other than the e-mail address of the delivery destination, so send the broadcast e-mail without leaking the e-mail address of others. It is possible to do.

[0011] In the electronic mail delivery system, the electronic mail delivery system further includes a fifth storage unit that stores an email address that is not deleted from the email header of the email data as an email address that is not to be deleted, and the processing unit acquires the processing unit. The destination email address is deleted from the email header if the email address is a destination email address other than the destination email address and does not correspond to the read-out email address not to be deleted. .

[0012] In the present invention, the non-deletable e-mail address is stored in the fifth storage unit, and the e-mail data is transmitted without deleting the destination e-mail address corresponding to the non-deletable e-mail address from the e-mail header. This makes it possible to know the parties to whom the same e-mail has been sent (mail addresses not subject to deletion).

[0013] In the electronic mail delivery system, the electronic mail delivery system further includes a sixth storage unit that stores a mail address that delivers mail data without processing a mail header of the mail data as an unprocessed mail address, If the destination mail address acquired by the acquisition unit corresponds to the email address not covered by the cache, the second storage unit read the mail data. The mail header is not processed.

[0014] In the present invention, the non-processed mail address is stored in the sixth storage unit, and an electronic mail header is not carved for the destination corresponding to the non-processed mail address. Since mail can be delivered, it is possible to judge who sent the email and there is no loss of convenience. [0015] In the above-mentioned electronic mail delivery system, the generation unit, as the delivery destination, when the transmission destination email address acquired by the acquisition unit corresponds to the non-processing target email address. It is characterized by generating an envelope that collectively includes the destination email addresses.

[0016] In the present invention, envelopes are generated so that mail data is delivered together for non-processed mail addresses that do not cover the mail header. Can reduce the load.

Brief Description of Drawings

FIG. 1 is a block diagram showing a configuration of an electronic mail delivery system in the present embodiment

FIG. 2 is a block diagram showing a configuration of an individual transmission unit in the electronic mail delivery system.

FIG. 3 is a flowchart showing the operation of the e-mail delivery system in the present embodiment.

FIG. 4 is a flowchart showing an operation of an individual transmission unit in the present embodiment.

FIG. 5 is an explanatory view showing one processing example of an envelope and a mail header of the electronic mail delivery system in the present embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of the electronic mail delivery system in the present embodiment. The electronic mail delivery system 1 shown in FIG. 1 includes a receiving unit 2, an encryption processing unit 3, a delivery processing unit 4, and a transmission unit 5. The encryption processing unit 3 includes an encryption determination unit 31, an encryption unit 32, and a password notification unit 33. The delivery processing unit 4 includes an individual transmission determination unit 41, an individual transmission unit 42, and a setting storage unit 43. The e-mail delivery system 1 is basically composed of a computer, and the processing of each part is executed by a program. This program can be recorded on a recording medium such as a CD-ROM, a magnetic disk, an optical disk, or a semiconductor memory, or can be provided through a network. The outline of the processing of each part is described below. [0020] The receiving unit 2 communicates with the client by SMTP (Simple Mail Transfer Protocol) to receive an e-mail. SMTP is known as an email transmission protocol. In SMTP, envelope information such as sender information (MAIL FROM) and destination information (RCPT TO) is sent from the client, followed by mail data (DATA) including a mail header and text. Mail data is delivered according to the destination information (RCPT TO) included in the envelope information. The client and the receiving unit 2 communicate with each other using SMTP, which is a general e-mail transmission protocol, so that the user can use mail transmission software that is normally used. The receiving unit 2 that has received the envelope information and the mail data stores the envelope information and the mail data in the memory of the receiving unit 2.

[0021] Encryption determination unit 31 acquires envelope information and mail data from receiving unit 2, and encrypts the file attached to the e-mail based on the acquired envelope information and mail data. Judge. The attached file is encoded into text data using BASE64 and included in the body of the mail data. The encryption judgment unit 31 outputs the envelope information and mail data to the encryption unit 32 when encrypting the attached file, and otherwise determines whether to send the envelope information and mail data individually. Output to part 41. If there is no file attached to the e-mail, there is no object to be encrypted, so the encryption determination unit 31 determines whether to send the envelope information and mail data individually, as in the case of no encryption. Output to part 41.

[0022] Also, for example, when a predetermined field is included in the mail header, or when a dummy mail address determined in advance is included in the destination information (RCPT TO), encryption is performed. The determination unit 31 can determine that the attached file is not encrypted. As described above, when the encryption determination unit 31 determines the encryption key using the mail header or the dummy mail address, the user can determine whether or not the attached file is encrypted for each email to be transmitted. Can be controlled.

[0023] The encryption unit 32 encrypts the attached file of the electronic mail, and outputs the mail data including the envelope information and the encrypted attached file to the individual transmission determining unit 41. In addition, the encryption section 32 is the password for decrypting the password and the envelope information password Output to the notification unit 33.

The password notification unit 33 transmits a password required for decrypting the encrypted attached file to the e-mail transmission source and the delivery destination as a password notification mail. The password notification mail is individually transmitted to the mail address described in the envelope information transmission source (MAIL FROM) and destination information (RCPT T 0).

[0025] The individual transmission determining unit 41 determines whether or not to perform the individual transmission process on the received electronic mail. The determination of whether or not to perform individual transmission processing is performed by, for example, the power that a predetermined field is included in the mail header, or a dummy mail address that is determined in advance is included in the destination information (RCPT TO). It is done by checking whether it is. Therefore, the sender of an e-mail can perform individual transmission processing for each e-mail to be sent by adding a predetermined field to the e-mail to be sent or adding a dummy e-mail address to the Bcc field. Can be controlled.

When individual transmission determining unit 41 performs an individual transmission process, envelope information and mail data are output to individual transmission unit 42. Further, when the individual transmission determining unit 41 does not perform the individual transmission process, the envelope information and the mail data received by the individual transmission determining unit 41 are output to the transmitting unit 5. The transmission unit 5 transmits an e-mail to a higher-level mail server based on the input envelope information and mail data.

The individual transmission unit 42 stores the input envelope information and mail data in a memory included in the individual transmission unit 42. The individual transmitter 42 then divides and acquires the mail addresses one by one from the destination information (RCPT TO) included in the envelope information. If the email address other than the acquired email address is included in the To field or Cc field of the email header, the individual sender 42 deletes the email address from the email header and stores it in the memory. Remember. Furthermore, the individual transmission unit 42 generates envelope information including only the acquired mail address as destination information (RCPT TO) and stores it in the memory. Then, the individual transmission unit 42 reads the mail data obtained by processing the mail header and the generated envelope information from the memory and outputs them to the transmission unit 5.

[0028] The setting storage unit 43 sends the mail data without checking the mail header, and the mail not to be processed and the mail not to be deleted that does not delete the mail address from the mail header. Remember the address. Mail addresses that are not subject to processing and mail addresses that are not subject to deletion can be specified collectively by specifying a domain. For example, when registering the email addresses of all employees of the company, the company's domain is specified in the setting storage unit 43. The individual transmission unit 42 refers to the setting storage unit 43 to obtain the non-processing target mail address and the non-deleting mail address. The individual transmission unit 42 delivers the mail data without checking the mail header of the mail data when the mail address acquired from the envelope information corresponds to the mail address not to be processed. In addition, when the individual sending unit 42 tries to delete the destination email address with the mail header, if the destination email address to be deleted corresponds to a non-deletable email address, the destination email address is changed. Do not delete from mail header. In the present embodiment, the same email address is stored as the non-target email address and the non-target email address, but this is not limited to this. Excluded e-mail addresses may be set separately. As a result, for email addresses that do not require careful handling, email headers are not checked or deleted. It is possible to judge the power of the mail header and the strength of the mail header, and there is no loss of convenience.

[0029] Transmission unit 5 transmits an e-mail to an upper mail server (MTA: Mai 1 Transfer Agent) according to envelope information and mail data input from individual transmission unit 42, individual transmission determination unit 41, and password notification unit 33 To do. Communication between the sending unit 5 and the mail server is performed by SMTP.

Next, details of the individual transmission unit 42 will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of the individual transmitter 42. The individual transmission unit 42 includes an envelope input unit 421, a mail data input unit 422, a mail address acquisition unit 423, a mail header processing unit 424, and an envelope generation unit 425.

[0031] In the individual transmission determination unit 41, the envelope information and mail data of the e-mail subjected to the individual transmission process are input to the envelope input unit 421 and the mail data input unit 422, respectively, and stored in the respective memories. Remembered. [0032] The mail address acquisition unit 423 acquires the mail address one by one for the destination information (RCPT TO) force included in the envelope information stored in the memory of the envelope input unit 421, and the mail header processing unit 424 And output to the envelope generator 425. The processing performed by the mail header processing unit 424 and the envelope generation unit 425 described below is performed individually for each mail address acquired by the mail address acquisition unit 423.

[0033] The mail header processing unit 424 reads the mail data from the mail data input unit 422, and is unnecessary other than the mail address acquired by the mail address acquisition unit 423 from the To field and the Cc field of the mail header included in the mail data. The mail address is deleted and stored in the memory of the mail header processing unit 424.

The envelope generation unit 425 generates envelope information so that mail data is delivered to the mail address acquired by the mail address acquisition unit 423, and stores the envelope information in the memory included in the envelope generation unit 425.

The transmitting unit 5 inputs envelope information from the envelope generating unit 425, inputs mail data corresponding to the input envelope information from the mail header processing unit 424, and delivers the mail data to a higher mail server. As a result, email addresses other than the destination email address are deleted from the email header of the delivered email.

, Can prevent the leakage of email addresses of others.

[0036] In addition, the mail address acquisition unit 423 refers to the setting storage unit 43 to acquire a non-target mail address, and the mail header processing unit 424 does not delete it from the mail header! . Note that the mail address acquisition unit 423 does not generate envelope information for each non-target e-mail address when there are multiple non-target e-mail addresses in the destination information (RCPT TO). Generate envelope information including all non-target e-mail addresses and send it together. This can reduce the load on the server when delivering e-mail.

FIG. 3 is a flowchart showing the processing procedure of the electronic mail delivery system 1 in the present embodiment.

[0038] The e-mail transmitted from the client is received by the receiving unit 2 (S31). Receive If a file is attached to the e-mail, the encryption determination unit 31 determines whether to encrypt the attached file (S32). If no file is attached, go to S35. Even if a file is attached, if the mail header contains a predetermined field, or if a predetermined dummy address is included in the delivery destination! /, The encryption part 32 Proceeds to S35 without encrypting the attached file.

[0039] Subsequently, the attached file is encrypted by the encryption unit 32 (S33). The password notifying unit 33 individually transmits a password for decrypting the encryption as a password notification mail to all the delivery destinations (S34).

[0040] Subsequently, the individual by the transmission determination unit 41, the determination of whether or not to perform the individual transmission process by the individual transmission process performed determines whether a is performed (S35) ₀ individual transmission judging 41, the mail header one Is determined by whether or not a predetermined field is included in the address, or whether or not a predetermined dummy address is included in the destination. When individual transmission processing is not performed, the process proceeds to S37. Then, the transmission unit 5 distributes the mail data to the upper mail server based on the received envelope information.

[0041] When the individual transmission process is performed, the individual transmission unit 42 copies the mail data for each destination mail address of the destination information (RCPT TO) included in the envelope information. The individual sending unit 42 deletes the email address other than the destination email address in the To header and Cc field of the email header of the duplicated email data, and delivers the email data to the destination email address. Envelope information is generated (S36). The transmission unit 5 distributes the mail data to the upper mail server based on the envelope information generated for each destination mail address (S37).

Next, the individual transmission process will be described in detail using a flowchart. FIG. 4 is a flowchart showing individual transmission processing of the electronic mail delivery system 1 in the present embodiment.

[0043] The envelope information of the e-mail is input to the envelope input unit 421, and the mail data is input to the mail data input unit 422. Then, the mail address acquisition unit 423 acquires the mail addresses included in the destination information ( _RCPT TO) of the envelope information one by one (S41). The individual transmission determining unit 41 determines whether or not the acquired mail address is an individual transmission processing target with reference to the setting storage unit 43 (S42). When the acquired mail address is an email address that is not subject to individual transmission processing, the individual transmission determination unit 41 stores the mail address in the memory of the envelope generation unit 425 (S45), and the next mail Go to S46 to get the address.

[0045] When the acquired e-mail address is an individual transmission process target, the individual transmission determining unit 41 acquires the mail data from the mail data input unit 422 by the mail header processing unit 424, and sets the To of the mail header. The other person's e-mail address (that is, the e-mail address other than the acquired e-mail address but not the excluded e-mail address) included in the field and Cc field is deleted (S43). Then, the envelope generation unit 425 generates envelope information including destination information (RCPT TO) for delivery to the acquired mail address (S44).

If the above processing has been completed for all mail addresses of the destination information (RCPT TO) included in the envelope information, the process proceeds to S47. If there are still email addresses to be processed, return to S41 to get and process the next email address (S46)

[0047] Since e-mails are collectively sent to non-target e-mail addresses, the envelope generation unit 425 includes all of the non-target e-mail addresses stored in the processing of S45 in the destination information (RCPT TO). Envelope information is generated (S47). For non-target email addresses, the email header of email data is not processed and sent.

[0048] By the above processing, mail data in which the mail address of another person is deleted from the mail header and envelope information for individually delivering the mail data are generated for each destination mail address. E-mails can be sent individually to the upper mail server.

Next, how the electronic mail delivery system 1 according to the present embodiment divides envelope information and processes the mail header will be described with reference to the drawings.

FIGS. 5A to 5F are diagrams showing a part of envelope information and a mail header. The upper part of each figure shows the envelope information, and the lower part shows a part of the mail header. . The envelope information includes source information (MAIL FROM) and destination information (RCPT TO), and each value is shown on the right side. In the lower part of each figure, the From field, To field, Cc field, and Bcc field of the mail header are shown, and the value of each field is shown on the right side of each field.

[0051] FIG. 5 (a) shows a part of envelope information and a mail header created when a client sends a broadcast mail. According to the mail header shown in the figure, the sender is aa a@test.co.jp,

Five destinations are specified: taro@other.co.jp, jiro@other.co.jp, bbb@test.co.jp, saburo@test.co.jp, and ccc@test.co.jp. In the envelope information, the sender information (MAIL FROM) is aaa@test.co.jp, and the destination information (RCPT T0) includes the above five mail addresses.

FIG. 5 (b) shows envelope information received by the receiving unit 2 and a part of the mail header. In the Bcc field, saburo@other.co.jp and ccc®test.co.jp specified in the Bcc field are included in the force envelope information that is deleted when the client communicates with the receiver 2. Because it is included, mail data is also delivered to these mail addresses. The individual transmission unit 42 performs individual transmission processing based on the envelope information and the mail header shown in FIG. In the setting storage unit 43, it is assumed that a mail address that is not subject to individual transmission processing is set to have a domain of test.co.jp. The following describes how the mail address acquisition unit 423 acquires mail addresses one by one and checks the mail header.

[0053] The mail address acquisition unit 423 acquires the mail address of taro@other.co.jp from the upper envelope information in FIG. 5B input to the envelope input unit 421. The mail header processing unit 424 duplicates the mail data including the information in the lower part of FIG. 5 (b) input to the mail data input part 422, and the To field and Cc of the mail header shown in the lower part of FIG. 5 (b). Delete email addresses other than taro@other.co.jp that have a domain other than test.co.jp from the field. By processing the mail header in this way, the mail header becomes as shown in the lower part of Fig. 5 (c). The mail header shown in the lower part of Fig. 5 (c) is obtained by deleting jiro@other.co.jp from the Cc field of the mail header shown in the lower part of Fig. 5 (b). Ccc@test.co.jp is the setting storage unit Since it corresponds to an e-mail address that is not subject to segmentation set to 43, it remains undeleted from the Cc field. The envelope generation unit 425 generates envelope information for delivery to taro@other.co.jp, and the generated envelope information is as shown in the upper part of FIG.

Similarly, the mail address acquisition unit 423 acquires the next mail address jiro@other.co.jp and generates envelope information and a mail header as shown in FIG. 5 (d). The envelope information and email header shown in Fig. 5 (e) are obtained by processing saburo@other.co.jp.

FIG. 5 (f) shows envelope information and a mail header for transmission to a mail address set as a non-target mail address in the setting storage unit 43. The non-target email addresses are bbb@test.co.jp and ccc@test.co.jp. Since e-mails are sent to non-target e-mail addresses as before, the e-mail header is the same as that shown in the lower part of Fig. 5 (b), and the destination information (RCPT) in the upper part of Fig. 5 (f). (TO) is the same as that shown in Fig. 5 (b), except for the email address for which individual transmission processing was performed.

[0056] Therefore, according to the present embodiment, the received envelope information power e-mail address acquisition unit 423 that acquires the e-mail addresses one by one and the destination e-mail address other than the acquired e-mail address from the e-mail header. By including an email header processing unit 424 to be deleted and an envelope generation unit 425 for generating envelope information for distributing email data to the acquired email address, a destination email address included in the envelope information is provided. Each e-mail data can be sent individually, and the e-mail address other than the delivery address can be deleted from the e-mail header of the e-mail data to be sent. Broadcast emails can be sent without leaking.

[0057] According to the present embodiment, by storing the non-deletable e-mail address in the setting storage unit 43, for example, a specific e-mail address addressed to the company is not deleted from the e-mail header. Since e-mail can be delivered, it is possible to send e-mail addresses including the destination e-mail address without paying attention to handling such as the company's e-mail address. It is possible to judge whether a broadcast mail has been sent. [0058] According to the present embodiment, by storing the unprocessed e-mail address in the setting storage unit 43, for example, for a specific e-mail address that is addressed to the company without worrying about leakage of personal information. Since it is possible to deliver an e-mail without processing the mail header, it is possible to determine to whom the e-mail was sent without impairing convenience.

[0059] According to this embodiment, the mail data is sent to the transmission destination mail address that delivers the e-mail without modifying the mail header, so that the load when distributing the mail data is reduced. Can be reduced.

[0060] According to the present embodiment, the client and the receiving unit 2 communicate with each other using a general electronic mail transmission protocol (SMTP), so that the user can use the mail transmission software that is normally used. Therefore, the e-mail delivery system 1 can be used easily.

[0061] According to the present embodiment, whether or not the individual transmission determining unit 41 includes a predetermined field in the mail header, or whether or not a predetermined mail address is included in the transmission destination. If these conditions are met, and the individual delivery process is not performed, the user can control whether or not the individual delivery process is performed for each e-mail.

Claims

The scope of the claims

[1] a first receiving unit that receives an envelope including a destination mail address and stores the envelope in a first storage unit;

A second receiving unit that receives mail data including a mail header corresponding to the envelope and stores the mail data in a second storage unit;

An acquisition unit for acquiring each destination mail address included in the envelope from the first storage unit;

For each of the destination email addresses acquired by the acquisition unit, the second storage unit deletes the destination email address other than the destination email address from the email header of the read mail data, and stores the email data. A processing unit to be stored in a third storage unit;

A generation unit that generates an envelope including the destination mail address so that the mail data is individually delivered to each of the destination mail addresses acquired by the acquisition unit, and stores the envelope in a fourth storage unit; ,

The fourth storage unit reads the envelope, reads the mail data corresponding to the destination mail address included in the envelope from the third storage unit, and reads the mail data based on the envelope. A delivery department for delivery; and

An e-mail delivery system comprising:

[2] Do not delete from the mail header of the mail data !, and further has a fifth storage unit for storing the mail address as a mail address not to be deleted,

The processing unit is a destination email address other than the destination email address acquired by the acquisition unit and does not correspond to the non-deletable email address read out by the fifth storage unit. The e-mail delivery system according to claim 1, wherein the e-mail delivery system is deleted from the e-mail header.

[3] No further processing of the mail header of the mail data !, and a sixth storage unit for storing the mail address for delivering the mail data as a mail address not covered by the cache,

The processing unit has the sixth storage unit power read out non-processing target email address 3. The mail header of the mail data that is also read by the second storage unit is not cached when the transmission destination mail address acquired by the acquisition unit corresponds to The described email delivery system.

[4] When the transmission destination email address acquired by the acquisition unit corresponds to the unprocessed email address, the generation unit generates an envelope that collectively includes the transmission destination email address as a delivery destination. The e-mail delivery system according to claim 3.

[5] a step of receiving an envelope including a destination mail address and storing the envelope in the first storage unit;

Receiving mail data including a mail header corresponding to the envelope and storing the mail data in a second storage unit;

Obtaining each destination mail address included in the envelope from the first storage unit;

For each of the destination email addresses acquired in the step of acquiring the email address, a destination email address other than the destination email address is selected from the email header of the email data read out by the second storage unit. Deleting and storing the mail data in a third storage unit;

An envelope including the destination email address is generated and stored in the fourth storage unit so that the email data is individually delivered to each destination email address acquired in the step of acquiring the email address. Steps,

The fourth storage unit reads out the envelope, reads out the mail data corresponding to the destination mail address included in the envelope from the third storage unit, and based on the envelope, reads out the mail Delivering data; and

An e-mail delivery program characterized by causing a computer to execute.

[6] Do not delete from the mail header of the mail data !, and further include a step of reading the non-deleted mail address from the fifth storage unit,

The step of deleting from the email header is a step of obtaining the email address. The recipient email address is a recipient email address other than the recipient email address obtained in step 1 and does not correspond to the email address not to be deleted! /, And the recipient email address is deleted from the email header. The e-mail delivery program described in 5.

[7] Do not check the mail header of the mail data! /, And further include a step of reading out the mail address to be processed that is not subject to processing and the sixth storage unit

The step of deleting from the mail header includes the second storage unit when the destination mail address acquired in the acquiring step corresponds to a non-processing target mail address. The e-mail delivery program according to claim 5 or 6, wherein the e-mail header of data is not checked.

[8] In the step of generating the envelope, when the destination email address acquired in the step of acquiring the email address corresponds to the email address not covered by the cache, the destination email address is set as a delivery destination. The e-mail delivery program according to claim 7, wherein an envelope including a batch is generated.